Electric telephone system.



No. 697,009. Patented Apr. 8, I902.

W. E..PEMBLETON.

ELEGTRI'C'TELEPHONE SYSTEM.

(Applicltion Med Dec. 24, 1900.)

2 Shoeta-$heel I.

(No Modal.)

No. 697,009. Patented Apr. 8, I902.

W. E. PEMBLETON.

ELECTRIC TELEPHONE SYSTEM.

(Application filed min, 1900. (No Model.)

2 Shuts-Sho'oi 2,

UNITED STATES PATENT OFFICE.

\VILLIAM E. PEMBLETON, OF \VITTENBERG, VISCONSIN.

ELECTRIC TELEPHONE SYSTEM.

BPECZIFICA'I'ION forming part of Letters Patent N 0. 697,009, dated April 8, 1902.

Application filed December 24, 1900. Serial No. 40,878, (No model- To (ti/Z whom it 777/07 concern:

Be it known that I, \VILLIAM E. PEMBLE- TON, a citizen of the United States, and a resident of Wittenberg, in the county of Shawano and State of \Visconsin, have invented certain new and useful Improvements in Electric Telephone Systems; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention has for its object to eliminate resistance of the coils of call-signal magnetos from the talking-circuit of an electric telephone system, as well as to provide for testing at anyof the telephones whether said circuit is in use or idle, and, furthermore, to provide for automatic signaling of the cutting in and cutting out of said telephones, so as to guard against overbearing on the line or at a switchboard, said invention consisting in what is particularly set forth with reference to the accompanying drawings and subsequently claimed.

Figures 1 and 2 of the drawings are diagrams illustrating means for attaining the ob jects of my invention.

Referring by letter to the drawings, A B 0 indicate three parallel conductors constituting the line of an electric telephone system embodying myiinprovements. Between the conductors B O are bridged all the electric bells or their" equivalents for signaling calls, said conductors constituting one part of the talking-circuit of the telephone system and conductor A the other part of said circuit.

As herein shown, 1) indicates a switchboard. call-signal, and c a line-telephone call-signal, the magneto D of the latter signal being in permanent electric connection with conductor O aforesaid,

A movable contact device E ot the form herein shown or otherwise, as may be most convenient, is arranged between two contactpoints (Z c, normally clear of both, these points being, respectively, in electrical connection with conductors A B aforesaid. By touching contact it on pointd a cailwill be sent in on conductors A G, and if said contact be put in touch with point e the call will be sent on conductors B C. At the switchboard is shown a call-signal apparatus comprising a magneto D, wired to contact-springs d c opposite other contact-springs d c in electrical coir nection with conductors B C, said contactsprings being in the path of arms of a reciprocative device E, constituting a circuitcloser. The magneto D is also shown wired to opposite bow-contacts ff, and spring-coniacts g g h h are arranged to be brought in touch with said bow-contacts, these springcontacts being normally against stationary stops 2' on the switchboard. An insulated slide F is shown in Fig. 1, provided with a slot engaged by a guide-pin, this slide being arranged to move either pair of spring-contacts g g or 7t 7t away from stops i into touch with bow-contacts ff, and said spring-contacts are in flexible electric connection with the sleeves G and pins G of a pair of switchboard-plugs. Hence it will be understood that a call-signal may be made through either of the plugs, according to the adjustment of slide F, this method of signaling being independent of that above specified. Each plug sleeve G is exteriorly grooved at its forward end to form a head and neck, and said sleeve is insulated from the contact-pin G, engaged therewith, this pin being extended beyond the sleeve-heads The conductors B C are electrically connected to contactsjj in opposition to a contact-shoulder 7; on the usual tilt-hook lever H, upon which to hang the receiver I of a telephone when not in use. Under ordinary circumstances the shoulder 7c of the tilt-hook lever is held away from the opposing contactsj j by weight of receiver I in suspended position; but for the purpose hereinafter specified a pivotal latch m is shown arranged to be brought into position to prevent upward swing of said lever when said receiver is detached therefrom. The lever and receiver are in circuit with the secondary of the telephone induction-0011.1, the secondary circuit being closed, when said lever is permitted to swing up, and thereby cause touch of its shoulder in with the contacts jj aforesaid.

A contact-plate K in insulated connection with lever H is opposed by a contact-point m in circuit with the primary of inductioncoil J, the telephone-transniitter L, and local battery M, this circuit being closed when said lever swings up to cause touch of said plate and point.

In a circuit including receiver I and batte ryM is a'spring contact-blade n, opposedby a contact-point p, electrically connected to conductor B. and by rotation of a ratchetsaid striker can be rotated in but'one direction by which to prevent other than inter mittent momentary contact of said bladeand point. l rom the foregoingit will be readily understoodthat if latch m is positioned, as

herein shown, to prevent upward swing-of lever II when receiver I is taken 0% hook and the striker N rotated in the permissible direction to cause intermittent momentary con.- tact of blade 12 with point p a clicking will be heard in said receiver, due to currentfronr battery M, if the telephone-line is busy, but

not otherwise, the clicking being due to in-r t'erruptions of said current. In other words, if a talking-circuit be closed on the line and lever H held down when receiver I is removed therefrom intermittent clicking, due

to rotation of striker N, will be heard in said receiver then cut into the talking-circuit independent of the induction-coil J, this being evident from the direct wiring of said receiver in a circuit with conductor A, battery M, blade n, point 1), and conductor. B, as is clearly shown in Fig. 1. a 1

At the switchboard of the herein-described I telephone system a normally interrupted circuit is shown in connection with conductors I battery M, ratchet-wheel'striker N, a pair of AB andv including operators receiverlfa I striker-opposing spring-blade contacts 'n n,

wincidental to then'otary movement of'said' normally out of touch with the blades.

striker N is engaged bya detentto prevent and contact-points p 19, these points being The its rotation in other than one direction, and

" striker there will be intermittent momentary contact of blades n a and points 19 19 to ob:

tain impulses from battery M,wired in circuit with receiver I andconductors A B, and thus cause clicking in said receiver if said line is busy, but not' otherwise. It is obvious that v the means described in connection with the receiver at the switchboard for busy test of the line are virtually the same as those in connection with other receivers on the line for the same purpose, although there are some differences in the matter of detail.

,The tilt-hook lever II is shown provided with an upper arm H, having two pairs of acute-angle. edge shoulders q'q, the under side of the lower shoulders q being insulated, and arranged in the path of the arm-shoulders are spring-contacts 'r in circuit with the local battery and an'electric call-bell P or other audible electric signal incased in an arm of the transmitter L aforesaid. When the lever H is permitted to swing up and close circuits at K m and at 7c j j, the shoulders q q of its arinH will successively strike the contacts r to thereby close circuit audcause two operations of theaudible signal P- to thereby 1 indicate a cutting in oftheline-telephone of 'which's'aid lever constitutes a part; but in cutting out there will only-be one operation. of said signahbecause of theinsula'tion on the under side of the lowerpair of arm-shouL Q der s. Henceit will be understood that in case two parties are talking on the line and another party cu'ts in this cutting in'will be automatically signaled and the conversation need not be continued until the'third party- I cuts out, the cutting out being also'signaledgboard springjacks, each of which comprises acontact-thimble Q, opposite pairs of springcontacts 3 s, insulated from each other and the thimble, and another pair of spring-con tacts't t, insulated from each other, thefirst of these latter contacts being-longer than its companion. Contacts 25 t andthimble Q are respectively in electrical connection with conductors A B O, the contacts 8 being respectively in electrical connection with conduc tors A B and in the primary circuit ofthe 7 switchboard-telephone. I

in the secondary circuit of said telephone, and

The contacts 8 are the latter is provided with an audible signal P, similar to the one P aforesaid in connection with a line-telephone.

board-telephone adjacent to transmitter L thereof, and it is obvious that when a plugsleeve G is positioned in the thimbleQ to havejits head spread contacts 5 against contacts s the signal-circuit will be closed and parties conversing on the line notified of the cut-in by the switchboard operator; but when the-plug-sleeve is moved to bridge contacts it the signal-circuit-Will be broken by the separation of contacts 8 8'', due tothe clear-- anceihad by the neck of said sleeve. .In' the last-described position of the plug its sleevehead has touch against contact i and'itspin been shown and described, it is evidentthat succeeding a breaking of'the talking-circuits I20 there will be a momentary closing of the circuit'by which to signalcut-out, and it is fur-- 'ther evident that'the switchboard operator The signal P"is shown in the primary circuit of the switch-' When'the plug ICQ cannot cut in or out wi-thoutsignaling the fact, this being to guard against overbearing by said switchboard operator. r

In Fig. 2 isvshown a transmitter L", combined with an audible electric signal I that sounds when the switchboard operator cuts in or out, this transmitter and signal and a battery M being auxiliary to the operators transmitter R and another local battery M in primary circuit with the same. tors receiver is in secondary circuit with the single induction-coil J shown in common The operacargoes with the two transmitters. These telephone elements and the signal P are in electrical connection with the flexible conductors connecting switchhoardplugs in pairs, these plugs being similar to those above specified, and circuits are made and broken by the means hereinafter specified.

A lever S is provided with alateral contactarm T, that is normally caught in a springclutch it, the branches of which are insulated from each other, and said arm serves as a circuit-closer. A brush comprising parallel spring-contacts w 50 y, insulated from each other, is shown in the path of oscillative cou- Iact-arm T, and by means of the electrical connections herein shown touch of said arm with the brush-contacts will result in closing primary and secondary circuits, so that in case the line in use the parties conversing will hear si nal P when the switchboard operator is cutting in or out. iVhen arm T is caused to pass out of contact with the brush aforesaid and engage another spring-clutch Z, (the branches of which are insulated from each other,) a circuit is established through operators receiver, ind notion-coil .i, and one of the flexible conductors aforesaid, the operators transmitter R and battery M being also in circuit with said coil.

To prevent the operator .lrm ing the cut-out signal and then swinging arm T to again out in, a weighted swing-stop U is arranged in the path of said arm to be normally in vertical. position, the upper end. of this stop being made to form a right-angle notch facing the springclutch aforesaid. The arm T being swung from normal position to out in the operator, the swing-stop U moves out of the way of said arm incidental to pressure thereon; but when the reverse or cutout operation is performed said arm engages the notch oi tne stop before coming into touch with the brush by which to close the primary and secondary circuits, and it is required that the aforesaid arm be swung clear of the stop-point and beyond the brush before said stop can have automatic return to its normal position, as is evident from the dotted-line showing herewith. Another pair of switchboard-plugs are shown in Fig. 2 as having their flexible conductors wired in series with those described in connection with the cut-in and cut-out lever S, and another lever S, provided with a lateral contact-arm T, has the function of a circuit-closer, its arm being arranged to come in touch with a brush comprising spring-contacts w m 2 (insulated from each other) and after passing the brush in one direction to engage a spring-clutch Z", the branches of which are separated by insulation. The brush-contacts and clutch branches last specified are similar in arrangement and connections with the conductors connecting the second pair of plugs, and one of said clutch branches is put in electrical connection with a branch ol clutch Z aforesaid. An annular notched and weighted swingstop U is arranged in the path of con tact-arm T to prevent a switchboard operator from signaling cut-out and again cutting in without signaling. It also follows that before contact-arm T can be utilized the other contact-arm T must be in normal position; otherwise it would be possible to cut in with the lever of one set of plugs and signal cut-out with the lever of anotherset otplugs, and no matter how many sets there may be in series at the switchboard it requires that all the levercontrol contact-arms T shall be in normal position before any one of the contact-arms T can be utilized to cut in.

The showing in Fig. 1 is designed to illustrate a division of mytelephone system that may include another division embodying.

what is shown in Fig. 2, and supposing the switchboard operator at a terminal of the first division receives a call for a telephone in the second division the two divisions are connected by plugging and signals are given, as above described. The operator necessarily remains connected with the plugs in use until parties at connected telephones are ready to converse, and then incidental to cutting out of said oporator there is automatic signal to said parties, so that they may know that their conversation is not being overheard by. the aforesaid operator. It is also to be understood from the foregoing that no switchboard operator on the line can cut in without signaling the fact to parties that may be at the time in conversation on said line.

Having thus described my invention,-what I claim as new, and desire to secure by Letters Patent, is

1. An electric telephone system having a spring-contact and an opposing contact-point normally separated at each station, a telephone-receiver and a local battery in circuit with said contact and point, a one-way ratchetwheel operative against the spring-contact, the tilt-hook lever for said receiver,and means for holding the lever in normal position when said receiver is removed therefrom, whereby intermittent momentaryinterruptions of current from said battery occurring incidental to rotation of said wheel against said springcontact are then audible in the aforesaid receiver.

2. An electric telephone system having an audible signal at each station thereof arranged to influence a transmitter, and means for actuating the signal sim nltaneous with the opening and closing of the talking-circuit at the same station, whereby when the signal is made it will be heard in receivers connected on the line.

3. An electric telephone system having an audible electric signal in normally open circuit at each station thereof arranged to influonce a transmitter, andmeans for making and breaking said circuit simultaneous with the closing and opening of the talking-circuit at the same station, whereby when the signal is made it Will be heard in receivers connected on the line. b

4 An electric telephone system embodying tilt-hook levers each provided with a shouldered arm constituting a circuit make-andbreak device, an electric audible-signal de-' vice in a local circuit having terminals in the path of said lever-arm and a telephone-transmitter arranged to be influenced by the signal device.

5. An electric telephone system including a switchboard, an electric audible-signal device, the-transmitter ,of a switchboard-telephone arranged to be influenced by the signal device, and means for energizing said signal device simultaneous with closing and. opening of talking-circuit at the switchboard, as well as for preventing open signal beinggiven while the talking-circuit is closed at said switchboard. I

6. An electric telephone'system comprising a switchboard, an electric audible signal at the switchboard in a local circuit'electrically connected to the line, a transmitter arranged to be influenced by the signal device, switchboard-plugs electrically connected in pairs .and likewise connected witlrthe signal-circuit, spring-contacts insulated'from each other toconstitute a brush in said signal-circuit, a contact-arm movablebn an arc of a circle to operate as a circuit-closerin conjunc- I 7 tion With the brush, and a gravity swing-stop.

having the upper end thereofarranged in the path of said arm, this end of" the stop being the other on swing of the arm from normal position to pass thebrush, but engagement of said arm'inthe stop-notch preliminary to resai d brush on reverse mover contact with ment. t I y In testimony that I claim the foregoing I have hereunto set my hand, at Wittenberg,

in the county of Shawano and State of Wiscousin, in the presence of two witnesses.

WILLIAM E. PEMBLETON.

Witnesses: 7

WM. G. I-IEINs, THERESA DUMKE.

35 made with a right-angle notch facing in a direction away from the aforesaidarm when the g,

latter and said stop are in normal position, whereby there is no interference of one with i 

